COMPUTED TOMOGRAPHY–GUIDED BONE BIOPSIES FOR EVALUATION OF PROLIFERATIVE VERTEBRAL LESIONS IN TWO BOA CONSTRICTORS ( BOA CONSTRICTOR IMPERATOR )

SERUM FENTANYL CONCENTRATIONS AND BEHAVIOR ASSOCIATED WITH TRANSDERMAL FENTANYL APPLICATION ON HEALTHY CORN SNAKES (PANTHEROPHIS GUTTATUS)

Snakes are common household pets and frequently managed in zoos. Geriatric snakes commonly develop osteoarthritis, leading to a declining quality of life that often results in euthanasia. Anecdotally, the application of transdermal fentanyl patches (TFP) appears to contribute to clinical improvement, including increased activity level, in osteoarthritic snakes presumed to be in pain. This study evaluated serum fentanyl concentrations over time and the effects of TFP on the normal behavior of healthy, captive, adult corn snakes (Pantherophis guttatus) using constant video monitoring. Serum fentanyl concentrations were evaluated over 4 wk during 12.5 µg/h TFP application, and the results demonstrated long-lasting (>4 wk) serum concentrations that were consistent with analgesic efficacy in mammalian species during TFP application. At 4 wk of TFP application, mean serum fentanyl concentrations were 11.5 ± 5.5 ng/ml. Snakes were videotaped for 1 wk prior to and 2 wk after 12.5 µg/h TFP application, and behavior was evaluated by an ethogram. Behavioral changes associated with TFP application included decreased mean time spent active, decreased mean number of climbs, and decreased mean number of water visits; feeding behavior was unchanged. Overall, these results suggest that TFP application may provide safe, clinically effective analgesia in healthy corn snakes for at least 4 wk without inducing deleterious side effects, and may therefore be appropriate analgesia for management of osteoarthritic snakes.

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

Salmonella are considered a part of the normal reptile gut microbiota, but have also been associated with disease in reptiles. Reptile-associated salmonellosis (RAS) can pose a serious health threat to humans, especially children, and an estimated 6% of human sporadic salmonellosis cases have been attributed to direct or indirect contact with reptiles, although the exact number is not known. Two literature searches were conducted for this review. The first evaluated reports of the prevalence of Salmonella in the intestinal tracts of healthy reptiles. Salmonella were most commonly detected in snakes (56.0% overall), followed by lizards (36.9%) and tortoises (34.2%), with lower detection rates reported for turtles (18.6%) and crocodilians (9%). Reptiles in captivity were significantly more likely to shed Salmonella than those sampled in the wild. The majority of Salmonella strains described in reptiles belonged to subspecies I (70.3%), followed by subspecies IIIb (29.7%) and subspecies II (19.6%). The second literature search focused on reports of RAS, revealing that the highest number of cases was associated with contact with turtles (35.3%), followed by lizards (27.1%) and snakes (20.0%). Reptiles associated with RAS therefore did not directly reflect prevalence of Salmonella reported in healthy representatives of a given reptile group. Clinical symptoms associated with RAS predominantly involved the gastrointestinal tract, but also included fever, central nervous symptoms, problems with circulation, respiratory symptoms and others. Disease caused by Salmonella in reptiles appears to be dependent on additional factors, including stress, inadequate husbandry and hygiene, and other infectious agents. While it has been suggested that reptile serovars may cause more severe disease than human-derived strains, and some data is available on invasiveness of individual strains in cell culture, limited information is available on potential mechanisms influencing invasiveness and immune evasion in reptiles and in RAS. Strategies to mitigate the spread of Salmonella through reptiles and to reduce RAS focus mostly on education and hygiene, and have often been met with some success, but additional efforts are needed. Many aspects regarding Salmonella in reptiles remain poorly understood, including the mechanisms by which Salmonella persist in reptile hosts without causing disease.

Survey of Post-Cranial Skeletal Pathology in Snakes

Previous reports on skeletal pathology in captive snakes did not clarify the relationship of lesions to captive or free-ranging status. In this study, post-cranial skeletons from 7,950 captive and free-ranging snakes in nine of the major North American collections were examined macroscopically, microscopically and radiologically for the presence of pathology. Micro-computerized tomography was performed on two skeletons on which surface microscopy failed to provide a definitive diagnosis. Osteomyelitis was identified in the vertebrae of 24 snakes and spondyloarthropathy in one snake. Neoplasia or congenital anomalies were not found. Osteomyelitis was four times as common in Viperidae than in Colubridae and twice as common as in Boidae, independent of captive or free-ranging status. A lytic lesion in the vertebrae of one snake was suggestive of fungal disease. The progression of bone lesions was greater in captive snakes, but the prevalence was independent of captive or free-ranging status. The results of this study indicate that bone alterations, previously proposed as neoplastic disease, in archival snake skeletons were most likely of infectious aetiology, and establish macroscopic examination as a useful technique for characterizing skeletal pathology in snakes.

USE OF COMPUTED TOMOGRAPHY-GUIDED PERCARAPACIAL OVOCENTESIS IN THE MANAGEMENT OF DYSTOCIA IN AN EASTERN BOX TURTLE ( TERRAPENE CAROLINA)

Computed tomography (CT)-guided percarapacial ovocentesis in an Eastern box turtle ( Terrapene carolina) was performed after medical management failed to resolve dystocia related to an irregular, oversized egg (38 × 30 × 35 mm). A 2.38-mm Steinmann pin was drilled through the carapace at the dorsal aspect of the seventh marginal scute, allowing introduction of an 18-ga needle through the carapace and oviduct into the egg using CT guidance. Contents of the egg (8 ml) were evacuated and CT reconstructions confirmed involution. The animal was administered oxytocin immediately after the procedure and passed the collapsed egg within 3 hr. The animal displayed no adverse effects from the procedure and the carapacial wound healed quickly without complication. CT-guided needle aspiration and biopsy techniques are common in human medicine, but less frequently utilized in veterinary medicine. This technique represents a novel, minimally invasive approach to ovocentesis that was used as an alternative to surgical intervention, in this case to resolve dystocia.

Orthopedics in Reptiles and Amphibians

Musculoskeletal disorders are a common cause for presentation of reptiles and amphibians to the veterinarian. A clinical approach to orthopedic cases starts with a thorough history and review of husbandry, and identification of any underlying or concomitant disease. Medical management is indicated for pathologic fractures. Traumatic fractures may require surgical intervention. Stabilization options include external coaptation and/or external and internal fixation. Special considerations must be given to shell fractures in chelonians. Many techniques used in mammalian practice can be applied to reptiles and amphibians, although some species may require prolonged healing times by comparison.

Orthopedic Diagnostic Imaging in Exotic Pets

Orthopedic diseases are a common problem in exotic pets. Diagnostic imaging modalities are more accessible and available in exotic animal veterinary medicine; the higher standards of care of the veterinary profession have progressed toward an increased offer of advanced imaging modalities. The literature on the use of diagnostic imaging modalities in orthopedic disease of exotic pets is scarce. This article discusses when to use the different diagnostic imaging techniques and reviews the imaging findings usually found in the most common orthopedic diseases in small mammal, avian, and reptile exotic pet species using different imaging modalities, especially radiography and computed tomography.

Aeromonas induced polyostotic osteomyelitis in a juvenile loggerhead sea turtle Caretta caretta

Bacterial bone infections have been occasionally reported in wild sea turtles. This study reports on a sub-adult Caretta caretta affected by Aeromonas hydrophila osteomyelitis, with extensive involvement of cranial and caudal flippers. The turtle was severely debilitated, had limited flipper mobility and showed signs of pain in reaction to manipulation. Radiographs and computed tomography revealed multiple lytic bone lesions. Since an infectious polyostotic osteomyelitis was suspected, the turtle was subjected to echo-assisted fine needle aspiration to characterize the etiology of the disease. Bacterial cultures and antibiotic susceptibility testing led to the isolation of Aeromonas hydrophila responsive to amikacin and doxycycline. Therefore, the turtle was treated with these antibiotics and monitored through repeat bacterial cultures and diagnostic imaging. The turtle was released 17 mo after admission, upon resolution of clinical signs. The documentation of this case provides a treatment approach that may improve the outcome of Aeromonas-associated osteomyelitis, especially in endangered wildlife species.

MANAGEMENT OF OSTEOMYELITIS CAUSED BY SALMONELLA ENTERICA SUBSP. HOUTENAE IN A TAYLOR'S CANTIL (AGKISTRODON BILINEATUS TAYLORI) USING AMIKACIN DELIVERED VIA OSMOTIC PUMP

An adult female Taylor's cantil (Agkistrodon bilineatus taylori) presented with marked spinal and mandibular osteomyelitis that cultured positive for Salmonella enterica subsp. houtenae, serovar IV 43:z4,z32:-. Progression of osteomyelitis was arrested by treatment using amikacin (0.026 mg/kg per hour) delivered via subcutaneous osmotic pump for 10 mo, replacing the pump every 4 wk. No adverse effects on renal function were appreciated throughout the course of therapy. Amikacin therapy was discontinued after improvement with treatment, but 5 mo later, bony lesions worsened, and an additional abscess formed at the previous pump site. The animal's condition declined and euthanasia was elected. Postmortem examination confirmed marked osteomyelitis with Salmonella infection of same serovar as the initial biopsy. This report highlights the pathogenicity of the S. enterica subsp. houtenae serovar and the ability to deliver effective amikacin dosage via osmotic pump to arrest osteomyelitis due to salmonellosis in a venomous snake.